Secret telegraph system.



w. P. PHILLIPS. SECRET TELEGRAPH SYSTEM.

APPLIOATIONTILED NOV. 8, 1909.

Patented July 5,1910.

flu ATTORNEYJ- WALTER IOLK PHILLIPS, F BRIDGEPORT, CONNECTICUT.

SEGB ET TELEGRAPH SYSTEM.

' To all whom 'it 71?, y concern."

, a result may Be it known t at I, WALTER P. Pnnmn's, a citizen of theUnited States, residing at Bridgeport, in the odunty of F airfield andState of Connecticut, have invented certain new and useful Improvementsin Secret Telegraph Systems, of which the following is a full, clear,and exactdescription.

In the transmission of messages bythe common system, in which themessages are received by a sounder, it 1s posslblefor any .person who isable to read Morse signals by sound to overhear the messages as they arereceived or transmitted, and important con1- munications, which underthe circumstances can not be coded, are thus in effect trans mitted withfull, publicity instead of being sent in secrecy. In fact, improperuse,has repeatedly been made by unscrupulous persons of information thusobtained, and such.

happen in any case when for any reason the message cannot be hrst trans:

'lated into a private code.

My present invention is designed to avoid this defect, and has for tschief ob ect to provide simple and effective means whereby the messages,although transmitted in ordinary Morse and without being coded, Wlll bey'utterly unintelligible to a Icy-stander and yet perfectly intelligibleto the sending and receiving operators. n

To this and other ends the-invention consists in the novel features andcombinations of elements hereinafter described, and more particularlypointed out in the appended claims. A convenient embodiment of theinvention is illustrated in the annexed drawing, and. referring nowthereto, Figure} 13 a plan view of the apparatus constitutingeastationSet, con'nrising sending and receiving devices. 1g. 2 is a diagramshowing the wiring of the system;

The apparatus at each station consists essentially, in addition to theusual key, 1, of a Morse sounder, 2, and a telephonic receiver, 3. Thesounder may be of the ordi--' nary kin d, on a local circuit, but in thepresemploy what is commonly ent embodiment I connected known as a linesounder, being directly to the line without the interposition of arelay. In either case, however, one Stop or contact of the sounder, ando the. rela also where the same is used, 1s made (lea or silent bysubstituting a stop ofsoft Specification of Letters laten t.

with the greatest ease.

Patented July 5, 1910.

Application filed November 8, 1969. Serial No. 528,761.

nection with the telephonicreceiver 25. The

latter may be of anyconreuieut type, such, for example, is. used inwireless teleg;v

raphy. I

9 is an ordinary two-point switch, mounted preferably on the same basea's'the key and sounder.

The wiring is SllU'Wl'l in Fig. 2, in which it will be seen the sounderand the telephonic receiver are in parallel, and that either may be cutout, while switch 9.

Normally, when the statibn is neither sending nor receiving, the switch9 is on point 10, (with the keysswitch it closed), and it will thereforebe seen that theline current, entering say at binding post (3, througl'iwire 12-, key 1, switch 9, sounder 2, and back to line through bindingpost 5. It will also be evident that; as the circuit is opened andclosed atsome other station the signals produced by the sounder 2 willbe imperfect or mutilated since only the back stroke of the armaturewill produce a sound, the forward stroke falling noiselessly on therubber pad or stop 4, Such mutilated sigthe otheris cut'iu, by the tiowsnails of course cannot be read by a by stander. Supposenow that thestation is called. The operator, having quickly and easily learned torecognize his call as' received by the mutilating sounder, at

once throws the switch 9 over to point 13,

thus cutting out the sounder and causing the current to flow frombinding post 6, wire 12,

post 7'back to the line. The sounder is thus idle, but in the telephonicreceiver the operator can hear and read the Morse signals In sending,the operator can leave the switch 9 ineither position, but preferablyputs it'on point 1.3 so as to out out the sounder.

From the foregoing it will be seen that the messages intended for thestation are delivered directly into the receiving operators ear, andthat at .every other similarly equipped station the signals are locallymu tilated at the sounder so asto be wholly unintelligible to thebystanders, but without beingin any way affected so far as the line isconcerned. In this Way complete secrecy is assured, no one but the lineoperators being able to get the full signals.

The embodiment herein specifically shown and described is convenient andthoroughly effective, but it is to-be understood that the invention canbe embodied in other forms without departure from its pro er spirit andscope as defined by the app'en ed claims.

$12 sw1tch, a Morse key ha vlng one terminal What I claim is: p

1. In a system of telegraphy of the kind described. for the secrettransmission of messages, a receiving instrument of the sounder typehaving a dead or silent arn'iature-stop, whereby signals receivedthereby will be enunciated in fragn'ientary or mutilated silent armaturestop', a receiving instrument of the telephonic type connectedin serieswith the line and in parallel with the firstnamed instrument, and aswitch for cutting filtfiel' instrument into or out of the line at W1 43. In a system of telegraphy of the kind described for the secrettransmission of mesa transmission line, a two-point connected to theline and the other to the switch, a receiving instrument of the soundertype having a dead or silent armature-stop and having one terminalconnected to the line and the other to one of the points of said switch,and a receiving instrument of the telephonic type having one terminalconnected to the line and the other terminal to the other point of saidswitch, whereby either instrum nt may be connected to the line in serieswith the key.

A. In a system of telegraphy of the kind described for the secrettransmission of mes sages, a station set comprising a Morse key,

and receiving instruments in parallel, one of ,sages, a station setcomprising a receiving instrument of the sounder type having a dead orsilent arniature-stop whereby signals received thereby Wlllbfienunciated in mutilated or fragmentary form, a receiving. instrument ofthe telephonic type a Morse key, and a switch for connecting eitherinstrument in series with the key at will.

6. In a system of telegraphy of the kind described for the secrettransmission of messages, a transmission line, a mutilating receivinginstrument for receiving Morse signals, and a telephonic receiverin'parallel with the former. i I.

In testimony whereof I affix lily-signature in the presence of twosubscribing Witnesses.

WALTER PQLK PHILLIPS.

Witnesses: 4

C. W. HEDBERG, N. B I ns'rrrnr.

